Device for connecting two coaxial components fixedly in terms of rotation

A device for fixedly connecting two coaxial objects for rotation together, wherein one object is radially outward and the other object is radially inward, the device comprising:

• an inner component around the inner object and an outer component at the outer object;
• the inner component being coaxially disposed inside the outer component, the outer component having an inner surface and the inner component having an outer surface and the surfaces being respectively shaped for defining between them and enclosing a tapered annular space, and means at the outer and inner components for making the annular space pressure tight relative to the outside;
• a tapered shape annular piston located in the annular space, the piston having respective outward and inward annular surfaces adapted for resting sealingly against the inner surface of the outer component and outer surface of the inner component;
• the piston being axially displaceable in one direction in the annular space selectively for bringing the annular surfaces of the piston to sealingly rest against the annular surfaces of the outer and inner components for pressing the components outward against the objects for causing the objects to rotate together and being axially displaceable in the opposite direction to discontinue the sealing resting;
• the device having axially opposite, front and rear end faces, with the front end face being toward the radially narrow end of the tapered annular space and the rear end face being toward the radially wider end of the annular space;
• a front annular pressure chamber being formed between the front end face of the device and the piston and between the inner and outer components;
• a rear annular pressure chamber being defined between the rear end face of the device and the rear of the annular piston and between the inner and outer components;
• a pressure medium feed duct for supplying pressure medium to each of the pressure chambers;
• the feed duct including a first duct leading to the front pressure chamber and including a second duct leading to the rear pressure chamber, the second duct extending within a wall of the outer component surrounding the annular space and opening into the annular space;
• the annular space having a front region more toward the front chamber than toward the rear chamber;
• the second duct opening into the front region of the annular space, sufficiently rearward in the annular space that even as the piston shifts axially through the annular space, the axial position of the opening of the second duct is covered by the annular piston;
• grooves extending axially along the annular space and connected respectively to the front pressure chamber and to the rear pressure chamber;
• at least one of the grooves defines a connection for a pressure medium between the opening of the second duct into the annular space and the rear pressure chamber;
• and
• the grooves connecting to the front pressure chamber extend rearwardly from the front pressure chamber and stop short of the region where the second duct opens into the annular space.